Review of standards for biodegradable plastic bags.

The Single Use Carrier Bags Charges (England) Order 2015 requires retailers to charge at least 5p for each single use carrier bag, except where exempted. Under section 18 of that order, the Secretary of State must— (a) complete a review of industry standards for the biodegradability of lightweight plastic material; and (b) lay a copy of a report before Parliament setting out the conclusions of the review, in particular— (i) whether it appears to the Secretary of State that there exists an industry standard appropriate for the purposes of an exclusion from the obligations specified in Part 2 on grounds of biodegradability; and (ii) if so, how that exclusion would be implemented. That review has now been completed. It found that there are a number of standards for plastic bag biodegradability. We will need to conduct further work before any of these could be used to exempt certain types of carrier bags on grounds of biodegradability. By the end of May 2016 retailers are required to report the number of bags that have been supplied, and the uses to which the proceeds of the charge have been put, after reasonable costs are deducted. The Government will use that opportunity to consider the early impacts of the charge. The Government will continue to consider the technical specification for a genuinely biodegradable bag, and will at that point further report on how an exemption for such a biodegradable bag can be implemented

Classification of Clouds Sampled at the Puy de Dôme Station (France) Based on Chemical Measurements and Air Mass History Matrices

A statistical analysis of 295 cloud samples collected at the Puy de Dôme station in France (PUY), covering the period 2001–2018, was conducted using principal component analysis (PCA), agglomerative hierarchical clustering (AHC), and partial least squares (PLS) regression. Our model classified the cloud water samples on the basis of their chemical concentrations and of the dynamical history of their air masses estimated with back-trajectory calculations. The statistical analysis split our dataset into two sets, i.e., the first set characterized by westerly air masses and marine characteristics, with high concentrations of sea salts and the second set having air masses originating from the northeastern sector and the “continental” zone, with high concentrations of potentially anthropogenic ions. It appears from our dataset that the influence of cloud microphysics remains minor at PUY as compared with the impact of the air mass history, i.e., physicochemical processes, such as multiphase reactivity

Cloud Microorganisms, an Interesting Source of Biosurfactants

A new scientific hypothesis states that biosurfactants from cloud microorganism origin could change the surface tension of aerosols and thus the mode of precipitations. In order to check this hypothesis, our team has screened a collection of 480 microbial strains isolated from cloud waters for the production of biosurfactants and showed that 42% of these strains were producing such molecules. In the present work, we isolated and identified by LC-MS-MS lipopeptides produced from three strains issued from this screening. Viscosin and massetolide E (cyclic lipopeptides) were produced by Pseudomonas sp. PDD-14b-2, and syringafactins (linear lipopeptides) were produced by Xanthomonas campestris PDD-32b-52 and Pseudomonas syringae PDD-32b-74. The critical micelle concentration (CMC) of these biosurfactants was determined using the pendant drop method. Finally, two approaches of molecular dynamics were used to model the conformation of viscosin and syringafactin A at the water-air interface: one is based on all-atoms simulation (CHARMM force field), while the other one on coarse-grain (CG) simulation (MARTINI force field). To conclude, this work shows how the biodiversity of the cloud microbiota can be explored to search and produce biosurfactants of interest both for atmospheric sciences and also for biotechnological applications

The study of the mercury cycle in polar regions: An international study in Ny-Alesund, Svalbard

Mercury (Hg) is a toxic pollutant and it can be strongly accumulated in the food chain, especially in Polar Regions. This paper presents a part of the work that has been on-going for 3-4 years in Ny-Alesund, Svalbard within the frame of an international collaboration. In Ny-Alesund in spring 2003, the atmospheric chemistry of mercury has been studied so as to better understand the formation of oxidized mercury species in the atmosphere that could be deposited onto snow surfaces. The role of snow as a potential source of mercury to the atmosphere or as a sink has also been approached to better understand the behavior of this metal. Chemical and biological processes seem to play a major role in Hg storage in snow. When melting, snow could be a major source of Hg into the various ecosystems and this toxin could therefore be accumulated into the food chain

Etude du métabolisme de Fibrobacter succinogenes S85 par RMN (synthèse d'oligosides et dégradation de fibres végétales)

CLERMONT FD-BCIU Sci.et Tech. (630142101) / SudocSudocFranceF

Etude du métabolisme de Rhodococcus rhodochrous lors de la photobiodégradation du 2-aminobenzothiazole (effet de l'immobilisation des cellules et rôle du fer)

La biodégradation du 2-aminobenzothiazole (ABT) a été comparée entre des bactéries en suspension dans l'eau et des bactéries immobilisées sur un support d'alginate. Trois processus de dégradation de l'ABT ont été étudiés : la photodégradation sous lumière solaire en présence du complexe Fe(III)-acide nitrilotriacétique (FeNTA), la biodégradation par la bactérie aérobie stricte Rhodococcus rhodochrous et la combinaison de ces deux processus. Le métabolisme de R. rhodochrous a été e tudié par RMN in vivo du 31P et du 13C : des informations importantes sur le métabolisme phosphoré et carboné ont été obtenues. La réponse de la bactérie face à divers stress a été évaluée et a montré sa capacité d'adaptation aux variations environnementales. La spéciation du fer pour son rôle important dans l'activation de la biodégradation d'ABT a été etudiée : complexes organiques, oxydes et oxy(hydr)oxydes de fer ont été testés pour connaître les formes biodisponibles pour R. rhodochrousCLERMONT FD-BCIU Sci.et Tech. (630142101) / SudocSudocFranceF

Biodegradation of polyethylene films with prooxidant additives

Prooxidanty představují slibné řešení problému kontaminace prostředí odpadem polyethylenových filmů. Prooxidanty urychlují foto a termooxidaci a štěpení řetězců a tím způsobují, že je materiál více přístupný biodegradaci. Ne zcela zodpovězená zůstává otázka samotné biodegradace, jejího mechanismu a zvláště faktorů, které ji ovlivňují a časového rámce, ve kterém k ní dochází. Předkládané review je zaměřeno na poskytnutí souhrné informace jak pro mikrobiology tak polymerní vědce, kteří musí na výzkumu těchto otázekProoxidant additives represent a promising solution to the problem of the environment contamination with polyethylene film litter. Prooxidants accelerate photo- and thermo-oxidation and consequent polymer chain cleavage rendering the product apparently more susceptible to biodegradation. The question not fully resolved remains the biodegradation itself, its mechanism and especially the factors influencing the time-frame in which it can occur. The presented review is aimed to provide comprehensible information for both microbiologists and polymer scientists, who need participate in the research leading to an understanding of the microorganism action on the oxidized polyethylene and to design of new materials

Microbiological meteorology : investigating atmospheric processes at the cross-roads of biological and physical sciences.

International audienc